High-transmittance solar cell front plate glass and preparation method thereof

Abstract

The present invention relates to a high-transmittance solar cell front plate glass and a preparation method thereof. The structure of the front plate glass includes a glass substrate and a glaze layer arranged on one surface of the glass substrate. The average light transmittance of the front plate glass is greater than 83%. The glaze layer is formed by firing the following materials in parts by weight: 15-35 parts of varnish and 65-85 parts of glass powder. The glass powder is composed of the following materials in 100% by weight: 35-40% SiO2, 1-5% Li2O, 2-5% MgO, 1-3% K2O, 7-15% BaO, 0-3% CaO, 10-20% ZnO, and 20-28% B2O3. The present invention forms a layer of high-transmittance glaze on the glass surface and subsequently tempers the glass. The obtained high-transmittance front plate glass is used for the light-facing surface of a solar cell, and the solar cell module has good photoelectric conversion performance.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic glass, and in particular to a high-transmittance solar cell front plate glass and a preparation method thereof. Background Art

[0002] Solar photovoltaic cells are devices that convert solar radiation directly into electricity through the photovoltaic effect. Similar to semiconductor photodiodes, when sunlight strikes the cell, it converts the solar energy into electricity. When multiple cells are connected in series or parallel, they form a solar cell array with high output power. To ensure sufficient power generation, solar photovoltaic modules utilize monocrystalline silicon solar cells within the module and are encapsulated with glass that has a transmittance of at least 91% within the solar spectrum's wavelength range (320 to 1100 nm). Outdoor solar photovoltaic power generation systems generate electricity by converting solar radiation into electricity. The intensity of the solar radiation received is the primary factor influencing power generation, and the intensity of the solar radiation received by the internal solar cells is related to the transmittance of the encapsulating glass.

[0003] Therefore, it is necessary to research and develop a high-transmittance glass front plate for solar cell modules to obtain better photoelectric conversion performance. Summary of the Invention

[0004] To address this technical problem, a high-transmittance solar cell front panel glass and its preparation method are provided. The present invention forms a layer of high-transmittance glaze on the glass surface, followed by glass tempering. The resulting high-transmittance front panel glass is used as the light-facing side of a solar cell module, resulting in a solar cell module with improved photoelectric conversion performance.

[0005] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] A high-transmittance solar cell front glass, comprising a glass substrate and a glaze layer disposed on one surface of the glass substrate, wherein the front glass has an average light transmittance greater than 83% within a wavelength range of 380-1100 nm;

[0007] The glaze layer is formed by firing the following materials in parts by weight: 15-35 parts of varnish and 65-85 parts of glass powder;

[0008] The glass powder is composed of the following materials in 100% by weight: SiO2 35-40%, Li2O 1-5%, MgO 2-5%, K2O 1-3%, BaO 7-15%, CaO 0-3%, ZnO 10-20%, and B2O3 20-28%. The low-melting-point glass powder of the present invention does not contain sodium oxide Na2O.

[0009] Furthermore, the glass powder is composed of the following materials in 100% by weight: SiO2 35-40%, Li2O1-5%, MgO 2-5%, K2O 2%, BaO 7-15%, CaO 0%, ZnO 10-20%, and B2O3 20-28%.

[0010] Preferably, the glass powder is composed of the following materials in a weight percentage of 100%: SiO2 39%, Li2O 5%, MgO 5%, K2O 2%, BaO 15%, CaO 0%, ZnO 12%, and B2O3 23%. With this composition, the glaze layer has an average light transmittance greater than 90% in the wavelength range of 380-1200 nm.

[0011] Furthermore, the glass powder is obtained by uniformly mixing SiO2, Li2O, MgO, K2O, BaO, CaO, ZnO, and B2O3 in a mixer according to a specific ratio, then melting and calcining the mixture at a temperature above 1000°C for at least 60 minutes to form a molten glass. The molten glass is then dripped into cold water for quenching to form a glass frit. The glass frit is then ground to a powder fineness D50 of less than 15 μm, preferably less than 5 μm. The small particle size of the glass powder facilitates light transmission, and when no pigment is added, the glaze layer approximates the natural color of glass.

[0012] Furthermore, the varnish includes water-based acrylic resin, polyester resin, and PVP water-based resin.

[0013] Furthermore, the glaze layer also includes additives such as dispersants, defoamers, and anti-settling agents. The glaze layer also includes 0.5-10 parts by weight of pigments, including colored pearlescent powders, optically variable pigments, inorganic metal pigments, and inorganic oxide pigments. The glaze layer can be customized to create a transparent front glass with a color such as green, red, or blue, depending on customer needs.

[0014] The above-mentioned method for preparing a high-transmittance solar cell front plate glass comprises the following steps:

[0015] Varnish, additives, glass powder, and pigment are mixed evenly according to a certain ratio to form a glaze layer slurry. The glaze layer slurry is then applied to one surface of a glass substrate, heated and cured, and then fired in a tempering furnace. After cooling, a high-transmittance solar cell front plate glass is obtained. Coating methods include screen printing, roller coating, and doctor blade coating.

[0016] Furthermore, the amount of glaze layer slurry applied to the surface of the glass substrate is such that the thickness of the glaze layer is within a range of 10-25 μm. The heating and curing temperature is 100-350°C, and the curing time is 30 seconds to 8 minutes. The firing temperature is 550-750°C, and the firing time is at least 60 seconds. The tempering temperature and time are set according to the thickness of the front glass. For example, for 2 mm glass, the tempering temperature is set to 600-710°C, and the processing time is 90-110 seconds; for 3.2 mm glass, the tempering temperature is set to 650-720°C, and the processing time is 110-150 seconds; for 4 mm glass, the tempering temperature is set to 650-730°C, and the processing time is 130-180 seconds; for 5 mm glass, the tempering temperature is set to 650-740°C, and the processing time is 180-250 seconds. The corresponding tempering parameters can be adjusted according to the glass thickness.

[0017] Beneficial technical effects:

[0018] The front glass of the present invention is formed by coating the glass surface once and then tempering it to form a highly transparent colorless or colored glaze layer. The front glass not only has a high transmittance of more than 83% for sunlight, but also has a pencil hardness of 9H, adhesion level 0, excellent weather resistance, and optional colors and patterns. In addition, the photovoltaic front glass of the present invention has a high surface resistance. The battery module made of the photovoltaic front glass of the present invention has a good anti-PID effect and good battery module performance under high temperature and high humidity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Graphs showing transmittance of the front glass of Examples 1 to 4 within a wavelength range of 380-1100 nm;

[0020] Figure 2 This is a physical picture of the front glass appearance of Example 1. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention and the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] Unless otherwise specifically stated, the numerical value set forth in these embodiments does not limit the scope of the present invention. Technology and methods known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology and methods should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments can have different values.

[0023] In the following examples, the experimental methods without specific conditions are generally measured in accordance with national standards. If there are no corresponding national standards, they are measured in accordance with the general international standards or the standards proposed by relevant enterprises.

[0024] The following examples do not include additives. Depending on the desired function, additives such as dispersants, defoamers, and anti-settling agents are added. For example, dispersants include modified polysiloxanes, anionic surfactants, high molecular weight surfactants, and modified acrylic polymers; defoamers include high molecular weight polymers, modified polysiloxanes, and hydrophobic polysiloxane compounds; and anti-settling agents include organically modified bentonite, polyethylene wax, polyamide wax, modified polyurea compounds, and synthetic waxes. These additives are commonly used in the industry.

[0025] The following front glass structure includes a glass substrate and a glaze layer arranged on one surface of the glass substrate. The light transmittance of the glass substrate body at 380-1100 nm is above 91.5%.

[0026] Example 1

[0027] A high-transmittance solar cell front glass, the front glass comprising a glass substrate and a glaze layer disposed on one surface of the glass substrate;

[0028] The glaze layer is formed by firing the following materials in parts by weight: 27.5 parts of varnish, 72.5 parts of glass powder, and 0 parts of pigment;

[0029] The glass powder is composed of the following materials in 100% by weight: 38% SiO2, 1.5% Li2O, 2.5% MgO, 2% K2O, 7.5% BaO, 3% CaO, 20% ZnO, and 25.5% B2O3. The glass powder is obtained by uniformly mixing SiO2, Li2O, MgO, K2O, BaO, CaO, ZnO, and B2O3 in a mixer according to a specific ratio, then melting and calcining the mixture at 1300°C for 2 hours to form a glass melt, dripping the mixture into cold water for water quenching to form a cracked glass frit, and then grinding the mixture in a grinder until the powder fineness D50 is less than 5 μm.

[0030] The ink varnish is a water-based acrylic resin ink varnish, which can be used immediately after mixing.

[0031] The method for preparing the high-transmittance solar cell front glass comprises the following steps:

[0032] Varnish oil, additives, and glass powder are evenly mixed according to a ratio to obtain a glaze layer slurry. The glaze layer slurry is coated on one surface of a glass substrate (glass substrate thickness 3.2 mm), heated and cured at 250°C for 2 minutes, and baked in a tempering furnace at 710°C for 130 seconds. After cooling, a high-transmittance solar cell front panel glass with a 25μm thick glaze layer on the surface is obtained. The glaze layer has a pencil hardness of 9H, adhesion level 0, and excellent weather resistance.

[0033] The average light transmittance of this embodiment in the wavelength range of 380-1100nm is about 86.11%. Figure 1 .

[0034] Example 2

[0035] A high-transmittance solar cell front glass, the front glass comprising a glass substrate and a glaze layer disposed on one surface of the glass substrate;

[0036] The glaze layer is formed by firing the following materials in parts by weight: 27 parts of varnish, 73 parts of glass powder, and 0 parts of pigment;

[0037] The glass powder is composed of the following materials in an amount of 100% by weight: 35% SiO2, 3% Li2O, 3.5% MgO, 2% K2O, 8.5% BaO, 3% CaO, 18% ZnO, and 27% B2O3. The glass powder is obtained by uniformly mixing SiO2, Li2O, MgO, K2O, BaO, CaO, ZnO, and B2O3 in a mixer according to a specific ratio, then melting and calcining the mixture at 1200° C. for 2.5 hours to form a glass melt, dripping the mixture into cold water for water quenching to form a cracked glass frit, cooling the glass frit to obtain a crushed glass frit, and then grinding the crushed glass frit in a grinder to a powder fineness D50 of less than 5 μm.

[0038] The varnish is a water-based PVP resin varnish, which can be used immediately after mixing.

[0039] The method for preparing the high-transmittance solar cell front glass comprises the following steps:

[0040] Varnish oil, additives, and glass powder are evenly mixed according to a ratio to obtain a glaze layer slurry. The glaze layer slurry is coated on one surface of a glass substrate (glass substrate thickness 3.2 mm), heated and cured at 300°C for 1 minute, and baked in a tempering furnace at 700°C for 150 seconds. After cooling, a high-transmittance solar cell front panel glass with a 23 μm thick glaze layer on the surface is obtained. The glaze layer has a pencil hardness of 9H, adhesion level 0, and excellent weather resistance.

[0041] The average light transmittance of this embodiment in the wavelength range of 380-1100nm is about 86.55%. Figure 1 .

[0042] Example 3

[0043] A high-transmittance solar cell front glass, the front glass comprising a glass substrate and a glaze layer disposed on one surface of the glass substrate;

[0044] The glaze layer is formed by firing the following materials in parts by weight: 26 parts of varnish, 74 parts of glass powder, and 0 parts of pigment;

[0045] The glass powder is composed of the following materials in an amount of 100% by weight: 39% SiO2, 3.5% Li2O, 5% MgO, 2% K2O, 10.5% BaO, 2% CaO, 15% ZnO, and 23% B2O3. The glass powder is obtained by uniformly mixing SiO2, Li2O, MgO, K2O, BaO, CaO, ZnO, and B2O3 in a mixer according to a specific ratio, then melting and calcining the mixture at 1200° C. for 2.5 hours to form a glass melt, dripping the mixture into cold water for water quenching to form a cracked glass frit, cooling the glass frit to obtain a crushed glass frit, and then grinding the crushed glass frit in a grinder to a powder fineness D50 of less than 5 μm.

[0046] The ink varnish is a water-based acrylic resin ink varnish, which can be used immediately after mixing.

[0047] The method for preparing the high-transmittance solar cell front glass comprises the following steps:

[0048] Varnish oil, additives, and glass powder are evenly mixed according to a ratio to obtain a glaze layer slurry. The glaze layer slurry is coated on one surface of a glass substrate (glass substrate thickness 3.2 mm), heated and cured at 200°C for 8 minutes, and baked in a tempering furnace at 720°C for 115 seconds. After cooling, a high-transmittance solar cell front panel glass with a 20-μm-thick glaze layer on the surface is obtained. The glaze layer has a pencil hardness of 9H, adhesion level 0, and excellent weather resistance.

[0049] The average light transmittance of this embodiment in the wavelength range of 380-1100nm is about 88.20%. Figure 1 .

[0050] Example 4

[0051] A high-transmittance solar cell front glass, the front glass comprising a glass substrate and a glaze layer disposed on one surface of the glass substrate;

[0052] The glaze layer is formed by firing the following materials in parts by weight: 30 parts of varnish, 70 parts of glass powder, and 0 parts of pigment;

[0053] The glass powder is composed of the following materials in 100% by weight: SiO2 38%, Li2O 5%, MgO 5%, K2O 2%, BaO 15%, CaO 0%, ZnO 12%, and B2O3 23%. The glass powder is obtained by uniformly mixing SiO2, Li2O, MgO, K2O, BaO, CaO, ZnO, and B2O3 in a mixer according to a specific ratio, then melting and calcining the mixture at 1200° C. for 45 minutes to form a glass melt, cooling the mixture to obtain a glass frit, crushing the glass frit, and then grinding the glass frit in a grinder until the powder fineness D50 is less than 5 μm.

[0054] The ink varnish is a water-based acrylic resin ink varnish, which can be used immediately after mixing.

[0055] The method for preparing the high-transmittance solar cell front glass comprises the following steps:

[0056] Varnish oil, additives, and glass powder are evenly mixed according to a ratio to obtain a glaze layer slurry. The glaze layer slurry is coated on one surface of a glass substrate (glass substrate thickness 3.2 mm), heated and cured at 350°C for 30 seconds, and baked in a tempering furnace at 715°C for 120 seconds. After cooling, a high-transmittance solar cell front panel glass with a 15-μm-thick glaze layer on the surface is obtained. The glaze layer has a pencil hardness of 9H, adhesion level 0, and excellent weather resistance.

[0057] The average light transmittance of this embodiment in the wavelength range of 380-1100nm is about 90.35%. Figure 1 .

[0058] Example 5

[0059] The materials used in the glass front plate of this embodiment and their preparation are the same as those in Example 4. This embodiment is a case of adding color, and specifically the glaze layer is formed by firing the following materials by weight: 26 parts of varnish, 70 parts of glass powder, and 4 parts of pearlescent white pigment.

[0060] The pencil hardness of the glaze layer of the glass front plate of this embodiment can reach 9H, the adhesion is level 0, and the weather resistance is excellent. The average light transmittance of this embodiment in the wavelength range of 380-1100nm is about 84.20%. The light transmittance curve is shown in FIG. Figure 1 .

[0061] Example 6

[0062] The materials used in the glass front plate of this embodiment and their preparation are the same as those in Example 4. This embodiment is a case of adding color, and specifically the glaze layer is formed by firing the following materials by weight: 27 parts varnish, 72 parts glass powder, and 1 part red iron oxide pigment.

[0063] The pencil hardness of the glaze layer of the glass front plate of this embodiment can reach 9H, the adhesion is level 0, and the weather resistance is excellent. The average light transmittance of this embodiment in the wavelength range of 380-1100nm is about 83.12%. The light transmittance curve is shown in FIG. Figure 1 .

[0064] Comparative Example 1

[0065] The preparation of the glass front plate of this comparative example is the same as that of Example 4, except that the ratio of the glass powder is: SiO2 35%, Li2O 2%, MgO 2%, K2O 1%, BaO 9%, CaO 3%, ZnO 16%, B2O3 20%, and Na2O 12%.

[0066] Comparative Example 2

[0067] The preparation of the glass front plate of this comparative example is the same as that of Example 4, except that Li2O does not exist in the ratio of the glass powder, and the corresponding weight of Li2O is added to SiO2.

[0068] The above front glass is used in 1722×1134mm modules using traditional 182mm square silicon wafers. The structure of the photovoltaic module from the light-receiving side to the backlight side is as follows: front glass (glaze-coated side facing inward), front encapsulant film, cell strings, rear encapsulant film, and back glass, laminated into a single unit. The laminator temperature is 130-145°C, and the lamination time is approximately 10-20 minutes. The cell strings are composed of 54 182mm crystalline silicon cells, cut in half, and connected in series and then in parallel. The front encapsulant film is a transparent film, which can be made of EVA, POE, or PVB. The rear encapsulant film is a black film, which can be made of EVA, POE, or PVB, and the back glass is clear glass. Alternatively, the rear encapsulant film is a transparent film, which can be made of EVA, POE, or PVB, and the back glass is black glass.

[0069] The performance of the solar cell module was tested, as shown in Table 1.

[0070] Table 1 Performance of solar cell modules using different front glass

[0071]

[0072] As can be seen from Table 1, the present invention causes a certain loss in the light transmittance of the glass substrate itself after providing a glaze layer on the surface of the glass substrate, but the loss is small. The light transmittance of the resulting colorless front glass remains above 86%, and the light transmittance of the colored front glass remains above 83%. The CTM value of the solar cell module made using the colorless front glass of the present invention is between 91% and 98%, and the higher the CTM value, the lower the degree of power loss in the module packaging. Because sodium can aggravate the PID phenomenon of photovoltaic modules under high temperature and high humidity environments, the present invention uses a sodium-free glass powder formula to make the module have better anti-PID performance (test conditions are humidity 85% RH, temperature 85°C, voltage of ±1500V, and the power attenuation and appearance changes of the front glass are observed after 96 hours). After the test, the glaze layer of the front glass has no defects in appearance. It should be noted that the glaze layers of all embodiments and comparative examples have almost no significant effect on power loss during the PID test, with power attenuation being less than 5%. However, as a front glass, it is required to have a good appearance (including a colored appearance). However, when the comparative example is subjected to an anti-PID test at a voltage of -1500V, the resistance of the comparative example glaze layer is smaller than that of the glaze layer of the embodiment of the present invention, resulting in a poor appearance and gray spots. As a front glass, this will greatly affect the appearance performance of the component.

[0073] In addition, the embodiment 5 and the embodiment 6 are colored front glass, which highlights the front color components through the back substrate of the battery, and has a more vivid and beautiful appearance.

[0074] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A high-transmittance solar cell front glass, characterized in that: The structure of the front glass comprises a glass substrate and a glaze layer arranged on one surface of the glass substrate, and the average light transmittance of the front glass in the wavelength range of 380-1100nm is greater than 83%; The glaze layer is formed by firing the following materials in parts by weight: 15-35 parts of varnish and 65-85 parts of glass powder; The glass powder is composed of the following materials in 100% by weight: SiO2 35-40%, Li2O1-5%, MgO2-5%, K2O 1-3%, BaO 7-15%, CaO 0-3%, ZnO 10-20%, and B2O3 20-28%.

2. The high-transmittance solar cell front glass according to claim 1, characterized in that: The glass powder is composed of the following materials in 100% by weight: SiO2 35-40%, Li2O 1-5%, MgO 2-5%, K2O 2%, BaO 7-15%, CaO 0%, ZnO 10-20%, and B2O3 20-28%.

3. The high-transmittance solar cell front glass according to claim 2, characterized in that: The glass powder is composed of the following materials in 100% by weight: SiO2 38%, Li2O 5%, MgO 5%, K2O 2%, BaO 15%, CaO 0%, ZnO 12%, and B2O3 23%.

4. The high-transmittance solar cell front glass according to any one of claims 1 to 3, characterized in that: The glass powder is obtained by uniformly mixing SiO2, Li2O, MgO, K2O, BaO, CaO, ZnO, and B2O3 in a mixer according to a proportion, then melting and calcining the mixture at a temperature above 1000°C for at least 60 minutes to form a glass melt, dropping the glass melt into cold water for quenching to form a glass frit, and grinding the glass frit until the powder fineness D50 is less than 15 μm.

5. The high-transmittance solar cell front glass according to any one of claims 1 to 3, characterized in that: The varnish includes one or more of water-based acrylic resin, polyester resin, and PVP water-based resin.

6. The high-transmittance solar cell front glass according to any one of claims 1 to 3, characterized in that: The glaze layer also includes an additive, which includes one or more of a dispersant, a defoamer, and an anti-settling agent; The glaze layer further comprises 0.5-10 parts by weight of a pigment, wherein the pigment comprises one or more of colored pearlescent powder, optical color-changing pigment, inorganic metal pigment, and inorganic oxide pigment.

7. The method for preparing a high-transmittance solar cell front glass according to any one of claims 1 to 6, characterized in that: The steps include: The varnish and glass powder are evenly mixed according to a ratio to obtain a glaze layer slurry, which is then coated on one surface of a glass substrate, heated and solidified, and fired in a tempering furnace. After cooling, a high-transmittance solar cell front plate glass is obtained.

8. The method for preparing a high-transmittance solar cell front glass according to claim 7, characterized in that: The amount of glaze layer slurry coated on the surface of the glass substrate is such that the thickness of the formed glaze layer is in the range of 10-25 μm; the heating and curing temperature is 100-350° C. and the curing time is 30s-8min; the firing temperature is 550-750° C. and the firing time is at least 60s.

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